Many of today's industrial sewing machines operate at extremely high speeds. To effect this end, adequate lubrication systems must be provided to dissipate heat and wear on the parts.
Pressurized lubrication systems are known in the art. In these systems, a sewing machine driven pump serves to withdraw lubricant from a reservoir and deliver it under pressure to the various mechanisms disposed throughout the machine frame. Because the pump is driven by the sewing machine, the circulation of lubricant is dependent on machine cycling. Therefore, there is an appreciable dely between the time the sewing machine is initially operated and the time optimum lubricant pressure and flow is effected to the operative mechanisms of the machine. In such systems, if a sewing machine is used to sew only a few stitches at a time in intermittent operation, it is possible for the sewing machine to run without ever reaching optimum lubrication pressure and flow throughout the entirety of the lubrication system.
Additional problems arise with pressurized lubrication systems. As with any lubricated part, operation is more efficient and effective after the lubricant has been warmed. That is, the power consumption for operating same and the lubricant flow characteristics are enhanced when operating with warmed lubricant. The machine lubricant in pressurized systems is warmed as a result of the frictional heat characteristics or build up of the machine. Unfortunately, up until now, there is an appreciable time dely between the time the sewing machine is initially operated and the time the lubricant has been warmed. Accordingly, during initial operation of the machine power consumption is greater and lubricant flow characteristics throughout the system are slowed.
In addition, problems have arisen because of the various speeds at which machines operate. Machines operating a lower speeds need a larger pump to deliver the necessary quantity of lubricant to the bearing surfaces. Machines operating a higher speeds required smaller pumps for delivering the necessary quantity of lubricant to the various parts requiring same. The effect on part inventory or stock is apparent.